The grue is a sinister, lurking presence in the dark places of the earth. Its favorite diet is
adventurers, but its insatiable appetite is tempered by its fear of light. No grue has ever been seen
by the light of day, and few have survived its fearsome jaws to tell the tale.

Theology 101

A cult's theology is binding on the god involved: it is possible for that god to believe (and see, just like Winston Smith in 1984) that other gods are mythical, or jumped-up demons, or failing older spirits, even while those gods actually exist and thrive and act in the cosmos, even while working against him.